Changing to standard BLE preamble

[Yair H]

Hi,

We are using nRF52833 with SDK 17.1.0.

We already have a FW that transmit and receive BLE data that is based on ble_app_uart example.

Now we are requiring changing the BLE preamble from 0x41 to 0x42 (see the picture below).

1. Is possible using the current SDK or we are requiring writing the BLE stack by ourselves?

2. could you supply as example code?

Thanks

[yuxuan.cai]

Hi,

By definition, the preamble is a fixed sequence of alternating 0 and 1 bits. Therefore, values like 0x41 or 0x42 do not meet this criterion. Could you please provide more details about your question?

Yuxuan

[Yair H]

Hi,

Thanks for your answer, but however can I modify it?

I would like to set it to 0x42.

Thanks.

[yuxuan.cai]

Hi,

Our hardware solution cannot achieve that as it is not conformant. See https://docs.nordicsemi.com/bundle/ps_nrf52840/page/radio.html#concept_hz4_cjl_4r__fig.packetonair for more details.


Yuxuan

[Yair H]

When I am pressing the above link this is the response that I got...

[yuxuan.cai]

Hi,

That's odd. Maybe you could access it from here. https://www.nordicsemi.com/Products/Development-software/nRF5-SDK/Download

Go to "Documentation" -> "Hardware drivers" -> nRF 52833 Drivers -> "Radio HAL" -> nrf_radio_preamble_length_t

Hope that helps!

Yuxuan